Bottle cap and method of manufacturing same



Feb. 28, 1933. A. H. WARTH BOTTLE GAP AND METHOD F MANUFACTURING SAME as a protecting Patented Feb. 28, 1933 UNITED STATES' PATENT OFFICE.

ALBIN H. WABTH, 0F BALTIMORE, HABYLAND. ASSIGNOB T0 CROWN GORI & mix- PANY, INC., 0F BALTIHOBE, MARYLAND, A CORPORATION 0l' NEW YORK BOTTLEl CAP AND HETHQD 0l' HANUIIACTUBLING'` SAIE original application led In, 5, 1999, Serial No. 860,895. Dividedand this 1930. Serial No. 499,548.

My invention relates to bottle caps and the method of making same, and moreI partlcular- 1y to a cap consisting of ametalllc s hell containing a cushion disk having what 1s known center disk, and to the method of applying this center disk.

Bottle caps of the type to which my lnvention relates have heretofore been extensively used for sealing bottles containing mmeral waters and other iuids having al deleterious action upon the cushion disk within the cap, Aparticularly when this disk is made of composition cork. Ordinarily theh facing center disk has been made of tin foil cemented or 'otherwise attached directly to the cushion disk, or secured thereto by means of a fibrous backing having applied thereto a dry adhesive made tacky by means of a thin film of moisture applied to the cushion disk.

It has been attempted to secure the facing disk upon the cushiondisk by means ofv a liquid cement, but this has proven impracticable because, in order to secure a satisfactory bond, it was necessary to apply the` adhesive in quantity having such thickness that, upon the application of pressure to secure the desired intimate relation between the facing disk and the'cushion disk, there was a tendency 0f the disk to slide into an eccentric position in 'relation to the disk. In order to permit the effective sealing of a bottle with a cap having a tin center or other protective facing,`it is essential that the Vfacing disk be accurately centered in relation to the cushion disk so as to avoid any possibility of the neck of the bottle sealing against the facing disk, since this would result in the presence of minute channels or voids at the point of contact of the facing diskwith the neck of the bottle. Furthermore, at the points where the line of Contact crossed the periphery of the disk, there would be exposure of a small area of the cushion disk to the contents of the bottle.

With the above conditions in mind, the object of my present invention is to provide a bottle cap having a protecting center disk secured in position by a fusible medium de void of moisture, and thus avoid any possibility of slippage of the disk while pressing it disk in application tied. Uctvober 9i,

into the necessary intimate relation with the cushion disk.

The medium used for securing the facin place is of itself water insoluble an acld resisting and, being fusible at low temperatures, will vform a very thin coating between the facing disk andthe cork so as to preclude the possibility, in the event of imperfections inthe facin disk, of the cork being attacked bythe fiui contents of a bottle. A medium which is itself elastic or resilient, such as gutta percha, is preferred, since the same will provide an elastic cushion for the of rupturing the latter.

The cementing medium may be readily fibrous disk `and thereby minimize the danger handled, is not affected by ordinary changes ,of temperature or atmospheric conditions,

may be readily cut to size simultaneouslywith the cutting of the facing disk so as to secure a bonding stratum coeextensive with the area of the facing disk, and may be quick- 1y fused to secure the desired bonding action between the facing diskand the cushion disk. y

In addition to the foregoing characteris- "ris tics, I am enabledA to effectively use a facing v disk of fibrous material, since the nature of the bonding medium is such as toA firmly adhere to hard finished papers as well as to natural cork or composition cork. In the commercial production of such caps, 1t 1s essential that the facing disk,'durin production, be cut from a strip of materia I and since the edges of the disk cannot beprotected by the same material used for waterproofing the surface 'of the disk, I have found it desirable, after the application of the facing disk, to apply, to the entire surface of the cap exposed interiorly of the cap,

a very thin protecting surfacing of water repellent material. This notonly serves to prevent adherence of the cork to the neck of the bottle, and to exclude atmospheric air vfrom the exposed portions of the cushion disk before the cap has been appliedto a bottle so as to prevent darkening of the cork by oxidation, but will at the same time, rotect'the perimeter of the center facin ldis to an extent to minimize likelihood o the absorptionv of moisture at the edge of the disk.

Bottle caps of thel general type of which K my invention relates must be produced at a 'cap embodying therein a metallic shell a vfinal stage; and

vcushion disk within said shell, a facin' disk of water repellent, gas impervious fibrous material, such `as a relatively hard, highgloss' or water-finishpaper provided with a coating of' resistant varnish, said disk being of smaller .diameter than, and concentric with, said cushion disk, anda thin stratum of a water insoluble, fusible, cementitious material, such as gutta percha co-extensive 1n area with said facing disk, between said facing disk and said cushion disk; and in such other novel characterlstics as are hereinafter set forth and described, and to the method of making said. caps, all as hereinafter set forth and described, and more particularly pointed out in the claims hereto appended.

Referring to the drawing:

Figure 1 1s a bottom plan view upon an enlarged scale of a bottle cap embodying the invention.

Figure 2 is a section on the line 2-2 of Fig. 1.

Figure 3 is a vertical section illustrating the 'first stage of applying the center disk to the cushion disk. v

Figure 4 is a similar view illustratlng the Figure 5 is a viewillustrating a stage intermediate those illustrated in Figs. 1 and 2,

used when it is desired to apply a wax finish `to the cushion disk.

Like letters refer to like parts throughout the several views. f

In the accompanying drawing, notwithstanding that the caps themselves are shown upon an enlarged scale, the dimensions of the facing disk and the intermediate bonding stratum are of greatly increased thickness as compared with the actual materials used even when compared with the enlarged `scale of the other parts of the cap.

A bottle cap embodying the invention consists of the usual metallic shell a having a fluted skirt b. Secured within this shell is a I lcushion disk c, which may be either of natural,

or of composition, cork. Composition cork is more extensively used than natural cork,

and the employment of a tin `or otherv center tively less than that of the cushion disk, so

that when the cap is applied to a bottle, the lip of the bottle Will be positioned between the facing disk and the skirt b, the contacting area being such as to bring the facing disk to a point at the inner edge of such contacting area.

' While heretofore tin'centers have been extensively used, it has Vbeen found impracticable to use paper disks for this purpose,

because in order to make them impervious to gas, and non-absorbent, the finish of the paper had to be such as prevented the formation of a sufficiently good bond between the facing disk and the cushion disk to permit the practical commercial production of such caps.

To correct this condition, it has long been the practice to bond a metal foil, such as tin or aluminum, to a fibrous backing, to which latter the cement would firmly anchor. With this construction of the facing disk it was the practice to apply` a dry adhesive to the fibrous backing strip and'to make this adhesive tacky by the application of moisture to the cushion disk immediately prior tothe coating of the facing strip and the applicatiolli of the disk cut therefrom to the cushion While caps, having a facing disk of the character immediatel above described, have beenf extensively use their production cost', as compared with the required low cost of such caps, has been very high.

Aside from the expense `of caps provided" with foil spots, their use has been extremely limited, due to the fact that foil is not suiiiciently resistant to acids and .alkalies l I am aware that it has heretofore been proposed to provide a cap with a center spot of paper, and that this is broadly covered in the United States patent to McManus, No. 1,339,066, granted May 4, 1920. The present invention constitutesan improvement upon the subject matter of saidpatent.

The use of center spots of paper on a commercial scale has not heretofore been economically practicable ,for several reasons. -1

col

it overlies. gain, the dimculty of applying V a' center spot ofpa. r to the cushion disk presents roblems a together different from the use o a facing disk coextensive, with the cushion disk; as for example the facing disclosed in my Patent No.11,656',614, granted June 17,11928. A facing which completely covers the cushion disk may be readily united .adhesivel to the sheet or blank fromwhichv the cushion disk` is stamped,\or in other words, the facing sheet and cushion sheet a're united adhesively, and the laminated disks unched therefrom. f But in applying a" ormed center. spot, as distinguished from a sheet, due to the fact that it is necessary to a'bsorb the moisture in the adhesive, and as heretofore-explained, during the period of' moisture evaporation the spot tends to become displaced.. This has presented a problem in large scale roduction, which manufacturers have not eretofore overcome.U

Furthermore, due to the moisture and gas absorbent properties of paper, the exposed edge of the paper spot is of an area which cannot be protected by a facing, such as foil or varn'ish, since the spot is punched from I sheets. This objection I have overcome by ausing a combination consisting of paper of f the character described and a liquid and gas resistant fusible adhesive..

' I have found that by using a paper of the character herein described, namely, a tough paper having a hard or high-gloss finish, for example, such as is termed a water-finish,

the samewill not fracture, has an inherent i resistance to liquids and gases and serves as an excellent carrier for an exposed or outer facing of-varnish and for a backing layer of water-insoluble, heat-fusible and acid and gas-resistant adhesive. I prefer an adhesive having these characteristics and which is also elastic so as to provide an elastic or cushion backing for the varnish layer and the rupturable paper layer.

Extensive commercial use of this new cap has established that it is resistant to acids and alkalies and', therefore, useful in connection with liquids with which a foil spot cannot be employed, and that it is at the same time substantially less expensive than a foil spot cap. Moreover, it does not present the mechanical diiiiculties'which are present in applying a foil center spot. The hard, tough paper serves as an excellent carrier for the varnish film as Well as for the gutta percha and insures coextensive varnish'and gutta percha films. The gutta percha serves not only as a medium for uniting the paper and varnish films to the cushion layer, but constitutes an acid and gas-resistant, waterinsoluble, backing layer, thereby preventing m0isture, acids or gases which penetrate the varnish film or paper from attacking the cushion layer. Moreover, the use of a hard paper having a Water-finish or high-gloss permitsthe use of even films of varnish and gutta percha, since the paper does not'absorb either the fused gatta percha or the varnish to any appreciab e extent. Consequently, it

is unnecessaryto employ'more varnish or` thicker gutta percha than is required tocover vcompletely the surfaces of the paper.

, v In the cap of my inve tion, the center disk d is composed of a glazed hard paper, such as is generally known as express paper, sulphite paper or bleached kraftpaper having' a water-finish, i. e., high-gloss finish. Such papers are, of themselves, independently of the finish, fairly non-absorbent, and when required for pasting purposes, are usually provided with a dry gummed surface. The process of producing 4such gummed paper results in a curl in the paper. i

While such hard tough pa ers are extremely desirable because of thelr inherent nonabsorbent, gas impervious qualities, their use in bottle caps of the type t'o whichV my invention relates was impracticable, prior to my invention, because of the diiculties of feeding and cutting previously gummed paerkand of cementing lsame to the cushion obviate these difficulties, I use v ungummed paper of the type above referred to, and secure it tothe cushion disk by means of a disk of what is known as gutta-percha tissue,

which material, in strip form, may readilyA be handled in a machine and collated with a facing disk paper strip so asto permit a disk of the paper and a disk of the gutta-perchaA to be simultaneously cut by theysame dies. This not only simplifies the' reduction of the cap, but results in a bonding stratum e between the facing disk and the cushion disk rcomposition cork, and to hard paper. Furthermore, it possesses the qualities of being non-absorbent and non-impervious to gases. The tissue itself is very thin, about a thousandth of an inch, and when softened, instantly adheres to the cork and to the paper, and is not subject to side sliding or slippage, such as liquid cements. The gutta-percha iisvnot affected by fruit acids, minerals, CO2

or other ingredients present in the fiuid contents of bottles with which such caps are desi ned to be used.

T e gatta-percha may be fused or melted at temperatures suiiiciently low to avoid in- In the cap of my invention, however, to.

jury the other previously assembled portions of thecap, and-will return to its former solid form at normal temperatures withconsiderable rapidity.

In the finished cap, particularly when` such ca s are desired for use with spring waiter or mineral waters, it is desirable, after the application of the center disk, to apply a very thin superficial coating f of water repellent material, such as paraiin, ceresin or. other waxes, throughout the exposed faces of the cushion and center disk. This coating serves `absorption of moisture through such raw edges.

A cap embodying theinvention lends itself to rapid roduction methods, which will now be descri d. l

Preparatory to the application of the centerdisk d to the-.cushion disk c, the latter is compl tely assembled in relation to the shell a. The caps, completely assembled, may be rapidly fed in relation to cutting dies g. and,

h, and as theyare brought under these dies, superimposed stripsl d of paper, and e of gutta percha tissueare fed between the die plate h and the punch g. With the descent of the punch g,disks are simultaneously cut from the strip d' and e', such disks being pressed by the punch upon the disk d with their centers concentric with each other and with said disk d. The punch g is maintained at an elevated temperaturerequired to melt the guttapercha of the strip e and make it tacky, so that substantially simultaneously with the pressing of the disksd and e against the disk c, the disks d' ande will be bonded together with sufficient permanency to ensure accurate positioning of the disk e and avoid likelihood of displacement of same thereafter. It is referable, after the disk e has thus been onded to the disk d, to thereafter subject them to continuing heat and pressure for a suilicient interval to ensure the complete fusion of the guttaflpercha and a close adhesion of every portion of the disk-cto the disk d.

For this urpose I have shown a carrier e' dsprin pressed plunger j.' In the drawing, have shown thepunch g and the plunger j as being heated by gas jets, but this is immaterial to the invention and other heating means maybe employed. It will be noted thr t by 'following' the methods above specified, the heat necessary fer the fusing of the gutta-ipercha is applied at the surface of the disk d, an'd that the time intervals are Asuiiiciently short to avoid any disk c. The very thin gutta-percha tissue Will melt very rapidly, and after the removal of the punch g or plunger j will solidify with great rapidity and forml a substantially im'- perceptible sti'atuin intermediate the discs c and d.

If it is desired to provide the cap with a superiicial wax surfacing throughout the area of the .cushion diskl 0 and cente1\y disk d, a very small quantity of wax, such as parain or ceresin wax or wax-compounds, may be delivered upon said disks-within the shell a following the application of the disk d to the disco, and prior to the application of heat and pressure through the medium of the car Arier z' and plunger j. Such heat and pressure will spread a drop of wax in a ver thin lfilm about 'the entire exposed face'of t e two disks, theraw edge of the diskd .also being coated with this Wax. l i

This thickness of thedisc d will be a proximately ive-thousandths of an linc y while the thickness of the binding stratum'e, in the ultimate product, will be relativelyv less than the thickness of the gutta-percha tissue, or a mere fraction of a thousandth of an inch. The wax surface stratum will also be but a mere Afraction of a thousandth of an inch, and is not perceptible to the eye, although sensible to the touch.

The glazed face of thedisk d does not require, a wax surfacing, and, so far as I have vbeen able to determine, most of the wax is .\expressed from this surface and forced from the disk to the exposed area of the cushion disk c.

If it is desired to rovide the vcap with a wax surface as descri ed, it is essential that this surface be applied after the center disk d has been 'assembled' in` the cap, since the presence of Wax uponv the surface ofthe cushion disk c, prior to the application :of the disk dl, would prevent a proper bonding of this disk d to the cushion disk c.

The glazed surface upon the strip d con-v sists of a waterproof compound consisting of resin, China-wood oil and a drier, and con'- taining a plasticizer.

.Express paper which has a high-gloss or Water-finish, sulphite vpaper and bleached l kraft paper are all well known commercial products. Y

This application vis a division of my copendingapplication Serial No. 360,895, filed -May 5,1929.

It -i's ,n'ot' my intention to limit the invention-tothe precise details herein described, it being'apparent that such may be varied withvout-departing from the spirit and scope of the invention.

I claim.: f

1. A bottle closure comprising a metallic shell, a cushion disk in said shell, a facing disk of yhard paperhaving a varnished outer surface, said disk being of smaller diameter than and concentric with said cushion disk, and a stratum of heat-fusible,acid-resistant and water insoluble adhesive material cextensive in area with the facin disk between the latter and the cushion dis and uniting the two disks.

2. A bottleclosure comprising a metallic shell, a cushion disk in said shell, a facing disk of hard, high gloss paper having a varnished outer surface, said disk being of smaller diameter than and concentric with said cushion disk, and a stratum of heatfusible, acid resistant and water insolublel adhesive material coextensive in area with the facing disk between the latter and the cushion disk and uniting the two disks.

3. A bottle closure comprising a metallic shell, a cushion disk in said shell, a facing disk of hard paper having a varnished outer surface, said disk being of smaller diameter than and concentric wlth said cushion disk, and a stratum of utta percha coextensive in area with the facl disk between the latter and the cushion dis and adhesively uniting the two disks.

4. A bottle closure comprising a metallic shell, a cushion disk in said shell, a facing disk of hard, high-gloss paper having a varnished outer surface, sa1d disk being of smaller diameter thanand concentric with said cushion disk, and a stratum of gutta percha coextensive in area with the the facin disk between the latter and the cushion dis and adhesively uniting the two disks.

5. A bottle closure comprising a metallic shell, a cushion disk facing said shell, a facing disk of express pa er having a varnished outer surface, said isk being of smaller diameter than and concentric withsaid cushion disk, and a stratum of gutta percha coextensive in area with the facin disk between the latter and the cushion disi and uniting the two disks. l

6. A bottle closure comprising a metallic shell, a cushion disk facing said shell, a facing disk of water-finish bleached kraft paper having a varnished outer surface, said disk being of smaller diameter than and con- 5 centric with said cushion disk, and a stratum of tta percha coextensive'in area with the facmgdisk between the latter and the cushion disk and uniting the two disks.

In testimony whereof I have hereunto set my hand.

ALBIN H. WARTH. 

